Many commercial, public or industrial buildings with many levels and many rooms avail of a control system for controlling the lighting, ventilation, air-conditioning etc. Devices such as lights or luminaires, light switches, light sensors, thermostats etc. with networking capability can be installed as part of a device network that can be centrally and automatically controlled. In a typical building such as a large office complex or a hospital, the device network may comprise many hundreds or even thousands of devices or nodes. Devices may be wireless and can communicate using a suitable wireless protocol. In a wired network such as an Ethernet network, neighbouring devices are physically wired together using a suitable connector such as a twisted pair or a co-axial cable. A ‘branch’ of a network refers to a number of devices wired together in series.
To set up such a wired network, the devices are first wired together according to a predefined plan. For example, a certain group of luminaires, for example all the luminaires in one room, can be wired together with a light sensor in a daisy-chain configuration. Each luminaire and sensor can be realised as simple bridges, i.e. with only two ports. One luminaire of the group of luminaires can in turn be wired to a ‘switch’ or hub located, for example, in a corridor outside that room, whereby the term ‘switch’ should not be confused with a ‘light switch’ or other manual switch, but is used in the context of a multi-port bridge. The hub in turn can be wired to other hubs or bridges. The order in which the devices are to be connected is usually specified on a plan generated using a program such as AutoCAD, which an electrician can consult while carrying out the wiring. The wired network then comprises a plurality of nodes (the devices) connected by branches (the connecting wires), whereby the nodes can be sent and receive messages (data packets) along the branches of the network.
Usually, the luminaires, sensors etc. of the network are controlled by some suitable control system running on a server, whereby the devices can be individually or collectively controlled by the control system. An example of a prior art dedicated lighting control system operates on a standard such as a digital addressable lighting interface (DALI) for the control of lights. In order to be able to correctly control the devices according to the wishes of the building's occupants or management, the control system must be informed as to which device is located at which physical location in the building. For example, in order to be able to switch on or off the lights in a particular room on a particular level, the control system must known which lights are located in that room. Giving the control system this information is referred to as ‘commissioning’, which is performed after the electrical installation of power cables and data cables has been completed. Unfortunately, the known methods of performing commissioning involve much manual input, and are time-consuming, labour-intensive and error-prone. In fact, the commissioning of a prior art lighting control system such as a DALI system can constitute up to one third of the total cost of the system.
Therefore, it is an object of the invention to provide a more reliable and cost-effective way of commissioning a network.